It's been a strange UFC career for Jackson, filled with as many bizarre and inexplicable moments as exceptional ones. As he goes out, complaining about a lack of respect, grumbling about what he perceives as the UFC's inept matchmaking, he leaves with another head-scratcher.

His departure from the biggest stage in mixed martial arts coincides with a lucrative Reebok endorsement deal that he says "makes me feel like a real professional athlete again." Jackson will appear in an ad campaign for a pair of training shoes Reebok is marketing as "All Terrain Vehicle."

Reebok held a news conference in Chicago on Tuesday to announce the deal with Jackson. The company’s name won't be seen anywhere Saturday during the Fox broadcast, though, because Reebok is not a UFC-approved sponsor and thus Jackson has been barred from wearing any of its branding into the Octagon.

His future in the sport is a mystery, though he figures to be appealing as a free agent to Bellator, the sport's second-largest promoter.

John Lynch, Reebok's head of U.S. marketing, said the company was interested in Jackson because of his personality and the image he portrays and not because of where he competes.

"We think his personality will transcend where he is at," Lynch told Yahoo! Sports. "I understand the UFC is the 800-pound gorilla in this sport. We get that. But we believe he's got a tremendous amount of juice on his own. He's a guy people have looked to as someone who transcends the sport that he's in. He has appeal simply beyond [fighting] and we just liked the fit of who he is."

Lynch said Reebok's desire isn't necessarily to be affiliated with the UFC brand, but rather be tied to Jackson's personality.

When he's in the right mood, Jackson is charming and funny and clearly a star-type personality. But he's just as often sullen and grumpy and complaining about hard-to-understand offenses.

For the last year-and-a-half or so, Jackson has moaned about the UFC's matchmaking and complained that he's been paired against wrestlers who he says just want to hold him to the mat.

Jackson is a wrestler whose forte has become his punching power. As the sport has evolved, opponents have learned how to neutralize his striking.

View gallery

.

Quinton 'Rampage' Jackson is shown running. (Courtesy: Reebok)

MMA involves more than just throwing haymakers, and Jackson said he gets that. But he isn't happy about what he said are cowards who in essence are looking to pin him.

"I never complain about people taking me down," Jackson said. "The only thing I've complained about is people taking me down and holding me. If somebody takes you down and holds you there and you can't get away from them, well, there are people in this sport who are really good wrestlers. If you're a guy and you're trying to punch somebody and somebody is always trying to take you down, you have to defend it and it just makes for a boring fight."

Lynch said Reebok isn't troubled by whatever issues Jackson has or has had with the UFC, because it wasn't looking to land a fighter per se to endorse the ATV shoe.

His outsized personality and unique training methods are what attracted the company to Jackson, Lynch said.

"There's an aspect of who he is that is more about the personality side of him," Lynch said. "There's a celebrity side of him and a fighter side of him. I'm not the one who is best to differentiate all of that, but for us, we're looking at him as a guy who embodies fitness and training."

UFC president Dana White said he would not rule out a new contract for Jackson, but said he found Jackson one of the most confounding athletes he's ever worked with.

The UFC has paid Jackson $15.2 million, White said, over his 11-fight UFC career and helped him to launch his movie career. But he said Jackson's mood swings made him difficult to predict.

"When he's the fun-loving, hysterical guy, he is a joy to promote and people love him," White said. "We've given him everything he's wanted. He wanted to make big money in the UFC and he's made millions and millions of dollars. He had a dream to do a big movie and he did the A-Team. He's complaining about matchmaking, but we're not doing anything differently with him. We're putting him against all of the top guys.

View gallery

.

Quinton 'Rampage' Jackson poses during a photoshoot. (AP)

"The way we think is, we want to be in business with people who want to be in business with us. Rampage is a complicated guy and you don't know where you're at with him on any given day. Anything is possible, but I don't know where Rampage's head is at and Viacom [the parent company of Bellator] is sitting on $5 billion cash. If they want to pay him a ton of money, they can. I don't know what is going to happen with him."

If Jackson knows, he's not saying. He's alluded to trying out boxing, but it's unlikely that he'll go that route to any serious degree. He could wind up in Bellator, or he could just play the celebrity circuit.

Jackson simply said he's going to remain in the spotlight regardless of his next act.

"My future holds a lot of stuff," he said. "I want to make people laugh and entertain them. I'm an entertainer really. That's really what I am. I might do more movies and do some commercials and like I said, my agent is talking about me getting a reality show to push my own brand.

"My fans can expect the unexpected. There is no telling what I might do or where I might be next."